Gas-engine.



E. P. PRALL.

GAS ENGINE.

APPLICATION FILED APR. 5', 1910.

' Patented Nov. 22, 1910.

2 SHEETS-SHEET 1.

Elvwantoz E. F. PRALL.

GAS ENGINE.

APPLICATION rum) n3. 5, 1010.

r Patented Nov. 22, 1910; 9 59. 3 2 SHEETS-SHEET 2.

EDGAR F. PRALL, OF NEW YCRK, N. Y.

GAS=ENGINE Application filed April 5, 1910. Serial No. 553.565.

To all whom it may concern:

Be it known that I, E GAR FLPRALL, a resident of New York, in the county and State of New York, have invented. certain new and useful Improvements in Gas-Engines; and I do hereby declare the follow ing. to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

This invention relates to rotary internal combustion or gas engines.

The object of the invention is to provide such an engine of high efficiency, comprising few and simple parts, low friction, and thorough packing against loss of'pressure, all as hereinafter described.

The invention consists in the construction hereinafter described and particularlyset forth in the claims.

'In the accompanying drawings which illustrate the invention and form part of the Specificationz-Figures' 1 and 2-are central transverse and longitudinal vertical sections respectively of the improved engine; Fig. 3 is a partial side elevation of the same; Fig.4 is a perspective view of a valve; Fig. 5 is a partial side view of the engine at right angles to Fig. 3; Fig. 6 is a partial section showing a modified Valve,

casing and piston packing; Fig. 6 is a broken section showing a modified packing; Figs. 7 and 8 are transverse sections showing valves with modified paekings;-Fi 9 is aplan view of a valveparty bro en away; Fig. 10 is a rear side view of an end plate of such valve.

The engine comprises a stationary cy-' lindrical casing 1, and an interior stationary drum 2 which is supported by its circular' heads 3 on a sleeve 4 mounted on'the main shaft 5 and supported inan end of the casing. The casing has an intake port 6, an exhaust port 7, and extending through an end of the casing, a suitable sparking plug 8 (not shown in detail) Opposite each other on the main casing body are two.

semicylindrical extensions 9, 10, which form supporting chambers for two rotary main valves 11, 12, which are alike, and each mounted on and turned by valve shafts: 13,

parallel with the ma n shaft and having of the casing,

gears 14- in mesh with gear 15 on the main shaft. Each shaft is suitably packed and is provided with ball bearings when desired, as shown. v

The main shaft 5 has a flange or enlargement 16 to which is secured a circular plate or disk 17 forming part of the rotary piston structure and rotatable in thespace between the casing and the proximate inner head 3. Around the outer portion of disk 17 are grooves for packing rings 18, behind which may be springs to maintain the rings continuously in firm contact with the outer casing notwithstanding wear incident to use. In a similar space at the opposite end and rotatable on the sleeve 4, by a ball bearing, is a second circular body or disk 17*, also packed toward the outer Specification-of Letters Patent. Patented Nov. 22, 1910.

edge. The 'ends of the drum 2 also have packing rings, 18*,on the sides adjacent disks 17, 17*. Instead of or in addition to rings 18,18 in the faces of disks 17, 17 and 3 expanding packing rings 180, 181, may be used in their peripheries. Secured to and connecting said disks 17, 17 at diametrical points are two cross plates or pistons 19, 19, adapted to divide and to be carried around in the annular piston chamber between the. casing andinner drum.

The valves 11 and 12 are each as long as the piston, and each has two segmental heads or. parts 20, each occupying a quadrant of its valve chamber, the intermediate quadrantsof the valve body being removed leaving two opposite concave sides 21. These valves are made and. kept tight, as hereinafter described. 1

The inner drum 2 is formed with concave segments 22 the outer surfaces of which face the valve extensions 9, 10 and have a correeponding radius, so that the valvesin turn ng fit snugly into said concave portions. The valve shafts are thus brought nearer together than would otherwise be possible with the same size of valve, ample room is provided for the passage of-the pistons by the valves, and the several open ngs and closures are properly timed and effected without leakage of gas. The ends of drum 2 being circular extend beyond parts 22 and closely fitr against the ends of the valves as they pass through the depressions...

Over the upper valve chamber is secured a cap or'body 23 larger than sa d chamber whereby a compression chamber 24: is-

formed of considerable capacity.- This chamber communicates with opposite ports 25, 26 leading from the casingof va ve 11. Controlling said ports are valves 27, 27", .each having a stem and means for closing and openign it. For example, each rod has a spring 28 which'tends to close the valve, the rod outside the casing being connected to another rod 29 which extends into the nth of'a cam 30011 the shaft 13, the two ro s 29 being on; opposite sides of the cam and in 1 5. slightly diiferent planes at then operative tions'ofsaid cam. As the double cam 30 retates it opens one valve 27 as it allows the other 27* to close under influence of its spring. Each portion of the cam acts on its rod twice in arotation of the cam, and the portions of the cam are at right angles -to each other and act quarterly. v

The operation of the 'engme is as follows :Piston 19 moving up from the position shown in Fig. l draws'ga'solene or other suitable vapor mixed with a proper proportion of air through the inlet 6, and said piston when it'reaches thetop of the cylinder passes under valve 11 which in turning closes .the open way. The piston 19* has at the same time moved down and passed under or by the lower valve 12, and as it ascendsit compresses the vapor and air that "was drawn in by piston 19, said vapor and air being then prevented from escapingby valve 11 which. at this time blocks the way in front of "said piston 19, while it uncovers the right hand valved port and thence the gas is permitted to escape in being com; pressed into chamber 24 by valve 27 which "is now opened by its cam 30 for the purpose, said valve 27 being. closed byits spring as soon as the piston 19 arrives in position to pass under valve 11 and as the piston emerges on the other side of the valve the latter closes behind the piston thus blocking lthe way to the rear. The valve 27*, which is now behind the piston, opens and permits the compressed gas stored in chamber 24 and still under pressure to escape into the space between the valve '11, which has spring to revent back firing. At this junc hire an e ectric spark from the plug and suitable electric connections (not shown) ignites the gas, and the explosion (which cannot act backward by reason of the valves 11 and 27 having closed the open way) gives-an impetus to the piston which drives 1t down and around until'the exhaust 7 is reached, when the piston asses through the I concave space in the va ve 12 which has ends so as to be actuated'by diflerent por-' reached the correct position therefor. This piston in ascending on the other (right) side (the valve having been closed behind it) goes through the same operation as described in connection with the first piston.

By providing'the tw'o valves 11, '12, eachhaving the two concave sides, and cooperating with the two opposite pistons, said valves need only turn as often as the main shaft, whereby the friction is much less than with morerapidly turning valves such as have generally been emplo ed. While one piston 15 receiving the impu se of an explosion, the other piston is compressing a charge of vap'or and air for the compression chamber, and drawing in a fresh charge for the following piston to-compress. The valve 11 in rotating not only opens before and closes behind eachpiston in turn, but it controlscommunicati'on of the piston chamber with the port 25, and also the exit fro'mthe comprcs- 86 sion chamber-to the explosion chamber, and all without complication of parts or operation. Itis'important that valves 11 and 12 remain gas tight and to this end said valves may be made slightly tapered, the chamber 90 being of corresponding shape, and the valve being drawn in by a spring 32 as shown in b Fig. 6. This figure also shows how the outer flanged portions of the piston structure overlap the disks 3 making a close joint, and particularly if a packing (as 181) be provided between them.

The outer curvd surfaces of the valve 11,01 1 2,'whether the valve is cylindrical or tapered, may be provided with separate curved surface plates 33 havin inside ribs 34 fittinggrooves in the valve bo y to prevent leakage between theplates and body. Behind the plates are springs 35 which press the plates against the wall of the valve chamber. In Fig. 7 the 106 plates are shownconnected to'the valve adjacent the forward edges of the heads by hinges 36, the purbse being to keepi the forward edges of t e plates, 1n close to the valve body to prevent catching, while leav- '110 ing the other edges free to move outward as required. In Fig. 8 such hinges are omitted. The ends of, the main valves also have packing means. In Figs. 9 and 10. are shown end plates 37 having ribs "38 fitting rooves in a the valve body. Behind each p ate is an now uncovered the left hand port 26, and

thepiston, when valve 27* is closedby its outwardly-pressing spring 37.

My invention is notlimitedto all the dc.-

,.tails shown and described. For example, the

means for controlling the valves in ports 25, 26 may be-variedw'ithout departing from.

.the invention, althou h the cam-operating device is simple and 1s preferred. Soalso the form of said valves may be varied and other modifications made within the scope of the invention. 'Some of the improvements described areLapplicable to steam engines as well as gals engmes..-

It will be seen that by using two disks and connecting them by the pistons the .piston structure is rigidly connected to the shaft although one of the disks rotates on the fixed sleeve and is not directly connected to the shaft. The support of the pistons at both ends gives strength and prevents their being twisted out of position by the force of the explosions. Another advantage of the described two-disk construction is that it eliminates end thrust from the piston and main shaft since the gas pressure comes between the rigidlyconnected disks (and not between a disk and the headof the casing, as would otherwise be the case, therebycreating great friction).-

Having thus described the invention what I claim is r 1. An engine comprising a casing having an inlet and an exhaust and two opposite semicylindrical valve-chamber-extensions, a stationary drum central in the'casing, two opposite pistons between the casing and drum each being alternately a compression piston and a driven piston, a double-headed concave-sided rotary valve in each extension and adapted to permit the pistons to pass the sameopening the passage before and closing the passage behind them, a compres sion chamber with connection to the piston chamber on the compression side, and with the piston chamber on the explosion side, said connections being'on opposite sidesof one of said rotary valves, as set forth.

2. An engine comprising a casing having an inlet and an exhaust and two opposite valve-chamber-extensions, a stationary circular drum with concave sides facing said extensions in the casing, two opposite pistons between the casing and drum, a double-headed concave-sided rotary valve in each extension and adapted to project closely in to said concave portions as the valves rotate, a compression chamber with connection to the piston chamber on opposite sides of one of the rotary valves, and means for controlling said connections.

3. An engine comprising a casing and op posite valve-chamber-extensions, a station ary drum in the casing, a main shaft, opposite pistons between the casing and drum, rotary valves in said extensions ada ted to permit the pistons to pass, valveshafts parallel with the main shaft, driving means'between the me in shaft and the valve shafts, .a compression. chamber between the compression side and the-explosion side of one of the rotar valves, and separate valves controlling t e connection. 1

4. An engine comprising a easing and valve-chamber-extensions, a sleeve centrally supported in and by the casing, a shaft through the sleeve and easing, a drum supporte on said sleeve, a piston adapted to rotate between said casing and drum and having one end secured ,to'the shaft and the other end supported on said sleeve, and retary valves in the extensions.

An engine comprising a casing, a sta-. tionary inner drum, a shaft, a sleeve supported in and by the casing around the shaft, a piston structurehaving two disk-ends one fixed to the shaft between the casing and the sleeve and drum and the other having a bearing on said sleeve between the casing and drum.

6. An engine comprising a casing with opposite valve-chamber extensions, a stationary inner drum having circular ends and opposite concave segments, pistonsbetween the casing and drum, opposite rotary abutment-valves adapted-to fitclosely between said ends of the drum and in said coneavities as the valves rotate and to permit the pistons to pass.

' 7. An engine comprising a casing with a valve chamber, a rotary abutment-valve, an inner stationary drum, a compression chamberwith connections to opposite sides of said valve, means for controlling such connections, whereby gas is admitted under pressure on one side and passed'from the compresslon chamber to the explosion chan1- her on the other side, and means 'for igniting the gas on the latter side.

8. An' engine comprising a casing with a valve chamber extension, a rotary valve therein, a cap over said extension forming a compression chamber, said chamber having connections to opposite sides of said valve,

and means for controlling said connections.

9. An engine comprising a casing, a central drum with circular heads or ends, a piston structure also with circular ends and with a cross plate adapted to travel in the space, between the casing and drum, and packings between said ends.

' 10. An engine of,the character described comprising a casing, a double piston, amain shaft'therefor, opposite valve-chamber-ex tensions, rotary abutment valves therein, shafts for said valves, a driving co nection between ,theshafts, a compression camber, admission and outlet valves therefor, and cams driven by one of the shafts and controlling said latter valves.

11. A rotary abutment valve having two heads with convex outer faces comprising separate plates attached to the valve body, and means for maintaining tight joints between said plates and body.

12. A rotary abutment valve having two heads with convex outer faces comprising, separate ribbed plates engaging grooves in the valve heads, and springs pressing the plates outward.

13..A rotary abutment valve having two heads with convex outer faces and intermediate concavities, and-separate like-shaped In testimony whereof, I have signed this plates} forming. the ends of. the, alve and specification in the presence of two-subscrib- 10 connected thereto by tight oints. ing Witnesses.

j g 14. A rota'ry abutment valve slightly ta- 5 paring and having two convex heads and :concave between said heads, a. tapering seat Witnesses: for said valve, 3,119. a spring tending to hold R. MCNULTY, the vaive to its seat. J. L. PRALL.

EDGAR F. PRALL. 

